#region Copyright & License

//
// Copyright 2001-2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

#endregion

using System.IO;
using System.Security;
using System.Security.Principal;

namespace log4net.Util.PatternStringConverters {
  /// <summary>
  /// Write the current threads username to the output
  /// </summary>
  /// <remarks>
  /// <para>
  /// Write the current threads username to the output writer
  /// </para>
  /// </remarks>
  /// <author>Nicko Cadell</author>
  sealed class UserNamePatternConverter : PatternConverter {
    /// <summary>
    /// Write the current threads username to the output
    /// </summary>
    /// <param name="writer">the writer to write to</param>
    /// <param name="state">null, state is not set</param>
    /// <remarks>
    /// <para>
    /// Write the current threads username to the output <paramref name="writer"/>.
    /// </para>
    /// </remarks>
    protected override void Convert(TextWriter writer, object state) {
#if (NETCF || SSCLI)
  // On compact framework there's no notion of current Windows user
			writer.Write( SystemInfo.NotAvailableText );
#else
      try {
        WindowsIdentity windowsIdentity = null;
        windowsIdentity = WindowsIdentity.GetCurrent();
        if (windowsIdentity != null && windowsIdentity.Name != null)
          writer.Write(windowsIdentity.Name);
      } catch (SecurityException) {
        // This security exception will occur if the caller does not have 
        // some undefined set of SecurityPermission flags.
        LogLog.Debug(
          "UserNamePatternConverter: Security exception while trying to get current windows identity. Error Ignored.");

        writer.Write(SystemInfo.NotAvailableText);
      }
#endif
    }
  }
}